Haven – “Defeat and Victory” [Campaign 3 – Mission 4]

BY THE WAY!! I FOUND A BUG!!!! IF YOU USE THE "PETRIFY" SPELL WITH AN EARTH ELEMENTAL, THE ENEMY UNIT BECOMES IMMORTAL!! NEITHER GRIFFONS’ FLIGHT, NOR LIGHTNING CHAIN, NOR EVEN ATTACKING WORKS))))

This isn't a bug, it's a feature.
It's similar to the fact that you can't attack the nearest mermaid in melee combat, or you can only attack the nearest destroyer, and you can't attack the other enemies next to him.
And there's also another similar thing.
When the petrification wears off, you can attack the enemy normally.